Stumbled on this youtube video:
They sell various colored lenses to use but I’m thinking that a WS2812 led (or a bunch of them) mounted in a similar setup would let you adjust the color without needing different lenses. You could also have it change color as you move it…
Gonna try to make some sort of similar device… Perhaps a couple “AA” cells (or one of the Nokia LiPo’s we have) connected to a boost converter to get the needed 5 volts. Then a Nano (or smaller) uC driving the brightest WS2812 style LED(s). Mount it all in a short section of plastic tubing with a round translucent plexi end. This would give you the paint brush and if you made a small hood for it you’d get the spot light thingy he uses also…
Anyways food for thought…